Born Caleb Affleck, he is the younger brother of Ben Affleck. He portrayed Charlie in Tower Heist and the PI in Gone Baby Gone. He is also known for his roles in Good Will Hunting and Ocean's Eleven and in 2008, he was nominated for an Academy Award for Best Supporting Actor for his role in The Assassination of Jesse James by the Coward Robert Ford.
He appeared as Tom Myers in the first two American Pie movies.
He wrote, produced and directed a documentary about Joaquin Phoenix titled I'm Still Here in 2010.
He attended Columbia University and majored in physics.
He married his longtime girlfriend, Summer Phoenix, in June 2006 after her brother, actor Joaquin Phoenix, introduced them in 2000. He has a pair of sons named Indiana and Atticus.
- The meaning of the name Affleck: From Auchinleck, Scotland